Please re-ask the question and provide the model and guage or type of gun. "Acier Special" means special steel and is stamped on many different models.
Basically impossible to value with just the serial number.
You need to give more information. I assume it is a shotgun, but "Acier Special" just means it was made with "special steel" and we would need at least a model number to start looking for the manufacture date.
50-250 usd
50-500usd
With the serial number that you provided,your Browning 16 gauge shotgun was produced in the year 1949,by FN of Belguim for Browning.
Simply means 'special steel' in French.
$350-$850
1932
I am trying to find out the value of my Browning Acier Special C 12 guage Shotgun KG 8663 Serial number 307368
Basically impossible to value with just the serial number.
The 5G prefix to the serial number indicates that your browning was made by FN of Belguim for browning in 1965.
Basically impossible to value with no other information.